Virtualization

Publicerad 2015-10-23 11:16 av Johan Leitet

As a developer you will be surrounded by a lot of tools and you will probably be working with many different "stacks". To install all of these tools, servers, data-management systems etc. on your own system is not recommended. You will most probably end up with a rather unstable system with a need for different versions of tools for different tasks and projects. In the long run, this will give you a lot of problems.

Instead of installing all of these tools on our local computer we will use virtualization to our advantage. We can create a virtual computer on our computer and let the virtual computer have all tools we need for a certain task or project. If we create a virtual host (vhost) for each project, we do not need to worry about versions and clogging our own system with a lot of tools that might only be used once or twice while we test out a new system.

Virtualization in groups

When we work together in development teams, setting up a a common development environment is often a hassle. Some of the group members might be using Windows, some linux and others osx. In some cases the tools required are only available on two of the three platforms or are released with different bugs etc. In this case virtualization is the real saviour. By installing the same preprepared operating system in a virtual machine we can be sure our entire team is up and running in no time. If the system we set up is a clone of the system we use when we deploy the application we'll be even more satisfied.

Using Vagrant

For this course we will be using a system called Vagrant. Vagrant is a technique for virtualization on your local computer. That means that we can configure more complex virtual machines that you can easily run and use in your assignments. To get a quick introduction to Vagrant watch this video.

Installation

Installing Vagrant is quite straight forward. Because Vagrant needs a Hypervisor to function we also need to install one, in this case we will go with VirtualBox. If you already have another service like VMWare installed, please consult the Vagrant documentation to find out how to setup Vagrant without using VirtualBox.

The installation of these two applications should be pretty straightforward.

Basics

To start up a Vagrant machine one must have a Vagrant-file that points out how the virtual machine should be configured, which operating system, what libraries and application it will have and on which ports it will be listening. This file will be prepared for you in most cases, you just have to start it up and the whole thing will be installed.

You control your Vagrant machine through writing commands in your terminal. Below are the most common commands you need to know.

Command

vagrant up

Starts your virtual host using the settings in the file Vagrantfile

vagrant ssh

SSHs into your virtual host and logs you in.

vagrant destroy

Will destroy the virtual host and all it´s settings, not removing data in your vagrant-folder.